1. Field of the Invention
The present disclosure relates to a flex flat cable (FFC) structure, and more particularly, to an FFC structure having a surface where an embossment pattern is formed.
2. Description of the Prior Art
A flex flat cable (FFC) is a new type data line cable. The FFC is fabricated by an insulating material and a highly thin, flat tinned copper wire after the insulating material and the flat tinned copper wire are compressed in an automation device. A core is neatly arranged in the FFC, largely transmitted, structurally flat, compact in size, dismantled easily, and flexible so the FFC can be applied to all kinds of electronic products easily and flexibly. So the FFC as a data transmission cable is especially suitable for different high frequency bending conditions such as the connection of mobile components. The FFC can be plugged onto with a connector or directly welded on a printed circuit board (PCB).
The electronic products are designed to be compact in the modern tendency so the size of the cable used in the electronic products needs to be narrowed as well. The insulating material fabricating the conventional FFC is polyethylene terephthalate (PET). Although PET costs less and is easy to be compressed, the dielectric constant of PET and the dielectric dissipation factor of PET are greater. Besides, the resistance of the flat copper wire is greater under the limit of impedance specifications so the FFC is not beneficial to transmitting a high-speed data signal for a long distance. But, it should be taken into consideration that high costs and the difficulty in compression if other insulating material is substituted for the FFC. Besides, the thickness of a power flat copper wire and the thickness of a signal flat copper wire used in the conventional compression FFC is the same in specifications. When the power and the high-speed data signal are transmitted through the FFC at the same time, the thickness of the flat copper wire needs to match the specifications of the impedance. Under the limit of the specifications of the impedance, it is necessary to increase the quantity or width of the flat copper wire to enhance the withstanding current capability to conform to the specifications of the power. However, the increase in the quantity or width of the flat copper wire is disadvantageous of narrowing the size of the FFC.
Therefore, it is necessary and important to design a new FFC structure with which the high-speed data signal is transmitted longer and with which the size of the FFC becomes narrower more easily.